“Nine Inch Nails meets The Chemical Brothers” is how indie-rock trendsetter Sarah Lewitinn (aka Ultragrrrl) enthusiastically describes Innerpartysystem. Granted, she’s a little biased, having released the band’s 2007 The Download EP on her own Island Records imprint Stolen Transmission, but it’s doubtful she’d be working with them if she wasn’t an honest-to-goodness fan. And the Philadelphia-based foursome, set to release their full-length debut this spring, certainly lives up to that NIN/Chemical Bros. comparison, while also drawing on the band members’ emo roots to put its own distinct hardcore stamp on electro-dance-rock